U.S. patent application number 16/324556 was filed with the patent office on 2019-06-13 for atomic layer deposition apparatus and atomic layer deposition method.
The applicant listed for this patent is THE JAPAN STEEL WORKS, LTD.. Invention is credited to Tatsuya MATSUMOTO, Keisuke WASHIO.
Application Number | 20190177842 16/324556 |
Document ID | / |
Family ID | 61301769 |
Filed Date | 2019-06-13 |
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United States Patent
Application |
20190177842 |
Kind Code |
A1 |
WASHIO; Keisuke ; et
al. |
June 13, 2019 |
ATOMIC LAYER DEPOSITION APPARATUS AND ATOMIC LAYER DEPOSITION
METHOD
Abstract
An atomic layer deposition apparatus includes a film-forming
container 11 in which a film-forming process is performed, a
vertically movable stage 14 configured to hold a substrate 100, a
susceptor 50 held on the stage 14 and being configured to hold the
substrate 100, and a stage stopper 17 configured to stop rising of
the stage 14 and, when in contact with the susceptor 50,
partitioning a film-forming space S in which the film-forming
process is performed and a transporting space in which transport of
the substrate 100 is performed. Further, the susceptor 50 includes
an upper susceptor substrate holding portion 52B configured to hold
the substrate 100, and an upper susceptor peripheral portion 52A
arranged in a periphery of the upper susceptor substrate holding
portion 52B, wherein a susceptor deposition prevention member 15 is
provided on the upper susceptor peripheral portion 52A.
Inventors: |
WASHIO; Keisuke; (Kanagawa,
JP) ; MATSUMOTO; Tatsuya; (Kanagawa, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
THE JAPAN STEEL WORKS, LTD. |
Shinagawa-ku, Tokyo |
|
JP |
|
|
Family ID: |
61301769 |
Appl. No.: |
16/324556 |
Filed: |
April 24, 2017 |
PCT Filed: |
April 24, 2017 |
PCT NO: |
PCT/JP2017/016189 |
371 Date: |
February 9, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 21/68785 20130101;
C23C 16/45527 20130101; C23C 16/458 20130101; H01L 21/68735
20130101; C23C 16/4586 20130101; C23C 16/455 20130101; C23C 16/4401
20130101; C23C 16/44 20130101; C23C 16/45544 20130101 |
International
Class: |
C23C 16/455 20060101
C23C016/455; C23C 16/458 20060101 C23C016/458 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 31, 2016 |
JP |
2016-168994 |
Claims
1. An atomic layer deposition apparatus comprising: a film-forming
container in which a film-forming process is performed on a
substrate; a vertically movable stage provided in the film-forming
container; a susceptor held on the stage and being configured to
hold the substrate; and a stage stopper configured to stop rising
of the stage and, when in contact with the susceptor, partitioning
a film-forming space in which the film-forming process is performed
and a transporting space in which transport of the substrate is
performed, wherein the susceptor comprises a first susceptor
configured to hold the substrate, and a second susceptor arranged
in a periphery of the first susceptor, and a susceptor deposition
prevention member is provided on the second susceptor.
2. The atomic layer deposition apparatus according to claim 1,
wherein the susceptor includes an upper susceptor constituted by
the first susceptor and the second susceptor, and a lower susceptor
configured to support the upper susceptor, the upper susceptor
comprises an upper susceptor substrate holding portion including a
holding surface configured to hold the substrate, and an upper
susceptor peripheral portion positioned in a periphery of the upper
susceptor substrate holding portion and being arranged at a lower
position than the holding surface, and the susceptor deposition
prevention member is provided on the upper susceptor peripheral
portion.
3. The atomic layer deposition apparatus according to claim 2,
wherein a side surface of the upper susceptor peripheral portion is
positioned more inward than a substrate-side side surface of the
stage stopper, and the upper susceptor and the lower susceptor are
fixed to each other at the upper susceptor peripheral portion.
4. The atomic layer deposition apparatus according to claim 1,
wherein the susceptor includes an upper susceptor constituted by
the first susceptor and the second susceptor, and a lower susceptor
configured to support the upper susceptor, the upper susceptor
includes an upper susceptor substrate holding portion configured to
hold the substrate, an inert gas supply channel configured to
supply inert gas to the film-forming space via a gap between the
substrate and the susceptor deposition prevention member and via a
gap between the upper susceptor substrate holding portion and the
susceptor deposition prevention member is formed in the susceptor,
and an inert gas supply portion configured to supply the inert gas
to the inert gas supply channel is provided in the film-forming
container.
5. The atomic layer deposition apparatus according to claim 4,
wherein the inert gas supply channel formed in the susceptor is
constituted by an upper inert gas supply channel formed in the
upper susceptor, and a lower inert gas supply channel formed in the
lower susceptor, and the upper inert gas supply channel and the
lower inert gas supply channel communicate with each other.
6. The atomic layer deposition apparatus according to claim 4,
wherein an inert gas discharge port is formed by the gap between
the substrate and the susceptor deposition prevention member, and a
plurality of the inert gas discharge ports are formed along an
entire periphery of a vicinity of the upper susceptor substrate
holding portion, or the inert gas discharge port is continuously
formed along the entire periphery of the vicinity of the upper
susceptor substrate holding portion.
7. The atomic layer deposition apparatus according to claim 6,
wherein the inert gas is discharged from the inert gas discharge
port at a temperature within .+-.10% of a surface temperature of
the stage.
8. The atomic layer deposition apparatus according to claim 2,
wherein an inert gas supply channel configured to supply inert gas
from outside is provided in the susceptor, and an inert gas supply
port communicating with the inert gas supply channel is formed at a
position between the upper susceptor substrate holding portion and
the upper susceptor peripheral portion.
9. The atomic layer deposition apparatus according to claim 8,
wherein a plurality of the inert gas supply ports are formed.
10. The atomic layer deposition apparatus according to claim 8,
wherein an inert gas vent connected to the inert gas supply channel
is formed in the film-forming container.
11. The atomic layer deposition apparatus according to claim 1,
wherein the susceptor includes an upper susceptor constituted by
the first susceptor and the second susceptor, and a lower susceptor
configured to support the upper susceptor, the upper susceptor
includes an upper susceptor substrate holding portion configured to
hold the substrate, an inert gas supply channel configured to
supply inert gas to the film-forming space via a gap between the
substrate and the susceptor deposition prevention member and via a
gap between the upper susceptor substrate holding portion and the
susceptor deposition prevention member is formed in the susceptor,
an inert gas supply portion configured to supply the inert gas to
the inert gas supply channel is provided in the film-forming
container, and a stage stopper gas supply channel connecting the
inert gas supply channel of the susceptor and the inert gas supply
portion of the film-forming container is formed in the stage
stopper.
12. The atomic layer deposition apparatus according to claim 11,
wherein a plate electrode is arranged at a position facing the
stage, the stage and the susceptor are electrically connected to
each other, and the stage stopper and the susceptor are
electrically connected to each other via a metal O-ring.
13. The atomic layer deposition apparatus according to claim 11,
wherein the second susceptor is arranged at a position between a
substrate-side side surface of the stage stopper and a side surface
of the first susceptor just below the substrate.
14. The atomic layer deposition apparatus according to claim 11,
wherein the upper susceptor comprises the upper susceptor substrate
holding portion including a holding surface configured to hold the
substrate, and an upper susceptor peripheral portion positioned in
a periphery of the upper susceptor substrate holding portion and
being arranged at a lower position than the holding surface, a side
surface of the upper susceptor peripheral portion is positioned
more inward than a substrate-side side surface of the stage
stopper, and the upper susceptor and the lower susceptor are fixed
to each other at the upper susceptor peripheral portion.
15. An atomic layer deposition method comprising the steps of: (a)
mounting a substrate on a susceptor provided on a stage; (b) after
the step (a), introducing source gas from a gas inlet provided on a
film-forming container into the film-forming container such that
the source gas is absorbed onto the substrate; (c) after the step
(b), introducing purge gas from the gas inlet into the film-forming
container such that the source gas is discharged outside the
film-forming container; (d) after the step (c), introducing
reaction gas from the gas inlet into the film-forming container
such that the reaction gas is supplied onto the substrate and a
desired thin film is formed over a surface of the substrate; and
(e) after the step (d), introducing purge gas from the gas inlet
into the film-forming container such that the reaction gas is
discharged outside the film-forming container, wherein, during the
steps (b) to (e), inert gas is flowed in the film-forming
container.
16. The atomic layer deposition method according to claim 15,
wherein the inert gas is introduced into the film-forming container
via an inert gas supply channel formed in the susceptor, and the
inert gas is supplied to a side portion of the susceptor and a
film-forming space above the stage.
17. The atomic layer deposition method according to claim 15,
wherein the inert gas is introduced into the film-forming container
via a stage stopper gas supply channel formed in a stage stopper
configured to stop rising of the stage, and the inert gas is
supplied to a side portion of the susceptor and a film-forming
space above the stage.
Description
TECHNICAL FIELD
[0001] The present invention relates to an atomic layer deposition
apparatus and an atomic layer deposition method in which a thin
film is formed over, for example, a substrate.
BACKGROUND ART
[0002] The atomic layer deposition technique is a technique in
which a thin film is formed in a unit of atomic layer over a
substrate by alternately supplying gas of an element configuring
the thin film to be formed onto the substrate, and is known as a
technique for uniformly forming a thin film. In addition, the
atomic layer deposition method has advantages such as excellent
step coverage and excellent film thickness controllability as
compared to the CVD (Chemical-Vapor-Deposition) method.
[0003] When a process of forming a thin film is repeatedly
performed by the atomic layer deposition method, a thin film is
also adhered to an inner wall of a film-forming container. Further,
when the thin film adhered to the inner wall of the film-forming
container becomes thick, the deposited thin film peels off and a
portion thereof becomes particles. Therefore, it is necessary to
periodically remove the thin film adhered to the inner wall of the
film-forming container.
[0004] For example, Japanese Patent Application Laid-Open
Publication No. 2006-351655 (Patent Document 1) discloses a
processing method and a chemical vapor deposition apparatus which
use a deposition prevention plate and in which deposition materials
deposited on an inner wall of a chamber are covered by an amorphous
film.
[0005] In addition, for example, Japanese Patent Application
Laid-Open Publication No. 2000-243711 (Patent Document 2) discloses
a structure of a substrate processing apparatus in which a side
wall cover, a floor cover, an upper cover and a lower cover are
removably provided in a reaction chamber and in which inert gas is
flowed onto a lower surface of a susceptor.
[0006] Further, for example, Japanese Patent Application Laid-Open
Publication No. 2001-316797 (Patent Document 3) discloses a
technique in which a deposition prevention member is attached to a
substrate carrier of a film-forming apparatus such that adhesion of
a film onto a surface of the substrate carrier is prevented.
[0007] Furthermore, for example, Japanese Patent Application
Laid-Open Publication No. 2014-133927 (Patent Document 4) discloses
a technique in which a deposition prevention plate is provided in a
processing chamber of a plasma processing apparatus such that
adhesion of an insulating member to regions other than on a
substrate is prevented.
RELATED ART DOCUMENTS
Patent Documents
[0008] Patent Document 1: Japanese Patent Application Laid-Open
Publication No. 2006-351655
[0009] Patent Document 2: Japanese Patent Application Laid-Open
Publication No. 2000-243711
[0010] Patent Document 3: Japanese Patent Application Laid-Open
Publication No. 2001-316797
[0011] Patent Document 4: Japanese Patent Application Laid-Open
Publication No. 2014-133927
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0012] In the film-forming process by the atomic layer deposition
method, source gas (such as TMA: Tri-Methyl-Aluminum) used is
easily diffused and thus easily enters a small gap in the
film-forming container, thereby forming a film. For example, in an
atomic layer deposition apparatus in which a film-forming chamber
and a transporting chamber are partitioned by a stage stopper and a
stage or a susceptor, a gap is formed in the partitioned part which
is likely to become a point where particles are generated. That is,
the source gas having entered such a small gap becomes a film and
powders which cause generation of particles.
[0013] Particularly, in a large area type atomic layer deposition
apparatus configured to accommodate a large glass substrate, the
stage becomes larger as the substrate becomes larger, whereby a
flatness of the stage would decrease as the stage becomes larger.
As a result, a size of the gap in the partitioned part increases,
and generation of particles becomes more conspicuous.
[0014] Other problems and novel features will be apparent from the
description of the present specification and the attached
drawings.
Means for Solving the Problems
[0015] An atomic layer deposition apparatus according to one
embodiment includes: a film-forming container in which a
film-forming process is performed on a substrate; a vertically
movable stage provided in the film-forming container; a susceptor
held on the stage and being configured to hold the substrate; and a
stage stopper configured to stop rising of the stage and, when in
contact with the susceptor, partitioning a film-forming space in
which the film-forming process is performed and a transporting
space in which transport of the substrate is performed. Further,
the susceptor has a first susceptor configured to hold the
substrate and a second susceptor arranged on a periphery of the
first susceptor, wherein a susceptor deposition prevention member
is provided on the second susceptor.
[0016] In addition, an atomic layer deposition method according to
one embodiment includes the steps of: (a) mounting a substrate on a
susceptor on a stage; (b) after the step (a), introducing source
gas from a gas inlet of a film-forming container into the
film-forming container such that the source gas is absorbed onto
the substrate; and (c) after the step (b), introducing purge gas
from the gas inlet into the film-forming container such that the
source gas is discharged outside the film-forming container. The
atomic layer deposition method further includes the steps of: (d)
after the step (c), introducing reaction gas from the gas inlet
into the film-forming container such that the reaction gas is
supplied onto the substrate and a desired thin film is formed over
a surface of the substrate; and (e) after the step (d), introducing
purge gas from the gas inlet into the film-forming container such
that the reaction gas is discharged outside the film-forming
container, wherein, during the steps (b) to (e), inert gas is
flowed in the film-forming container.
Effects of the Invention
[0017] According to the above-described embodiment, it is possible
to suppress generation of particles in the film-forming container
and improve film quality of the thin film formed over the
substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a drawing of a schematic configuration showing an
example of a structure of an atomic layer deposition apparatus of a
first embodiment;
[0019] FIG. 2 is an enlarged cross-sectional view showing an
example of a main part of an inert gas supply channel of the atomic
layer deposition apparatus shown in FIG. 1;
[0020] FIG. 3 is a partially enlarged cross-sectional view and an
enlarged plan view showing an example of a structure of the inert
gas supply channel shown in FIG. 2;
[0021] FIG. 4 is a flowchart showing an example of an atomic layer
deposition method of the first embodiment;
[0022] FIGS. 5(a) to 5(d) are cross-sectional views showing an
example of a substrate in a procedure of a thin-film forming
process according to the flowchart shown in FIG. 4;
[0023] FIG. 6 is an enlarged cross-sectional view showing an
example of a structure of a main part of an atomic layer deposition
apparatus of a second embodiment; and
[0024] FIG. 7 is an enlarged cross-sectional view showing an
example of a main part of an inert gas supply channel of the atomic
layer deposition apparatus shown in FIG. 6.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
First Embodiment
Configuration of Atomic Layer Deposition Apparatus
[0025] A configuration of an atomic layer deposition apparatus 10
of the present embodiment will be described with reference to FIG.
1.
[0026] FIG. 1 is a drawing of a schematic configuration showing an
example of a structure of the atomic layer deposition apparatus of
the present embodiment.
[0027] The atomic layer deposition apparatus 10 of a first
embodiment is configured to form a thin film in a unit of atomic
layer over a substrate 100 by alternately supplying source gas and
reaction gas onto the substrate 100. At this time, the substrate
100 can be heated in order to enhance reaction activity. In the
first embodiment, TMA (Tri-Methyl-Aluminum) is used as an example
of the source gas, and plasma is generated during a film-forming
process in order to enhance the reaction activity. A parallel plate
electrode is used to generate plasma in the first embodiment;
however, the method to generate plasma is not limited thereto.
[0028] A film-forming container (also referred to as chamber) 11
provided in the atomic layer deposition apparatus 10 is a container
in which the film-forming process is performed on the substrate
100. Further, the film-forming container 11 comprises an injector
21, an outlet flange 31, a plate electrode 12, a stage 14 serving
as a counter electrode of the plate electrode 12, a susceptor 50
held on the stage 14 and serving as a substrate holder configured
to hold the substrate 100, and a high-frequency power supply
16.
[0029] The plate electrode 12 is arranged so as to face the stage
14, is provided above the substrate 100 with a film-forming space S
formed therebetween, and is supported by an insulating support 41
arranged on a side of the plate electrode 12. The insulating
support 41 is supported by a top-plate supporting portion 47
attached to a top plate 42. Further, an upper insulating deposition
prevention member 43 covering the top-plate supporting portion 47
and the insulating support 41 is provided on a peripheral portion
of the top-plate supporting portion 47 configured to hold the
insulating support 41.
[0030] In addition, an end portion of a surface of the plate
electrode 12 exposed in a direction of the stage 14 corresponds to
an end portion of the plate electrode 12, and a conductive plate
electrode deposition prevention member 13 is provided on the plate
electrode 12 exposed on a lower surface side.
[0031] The stage 14 is configured to hold the substrate 100 and
comprises a heater such that a temperature of the substrate 100 can
be adjusted to a desired temperature. For example, in a case of an
atomic layer deposition process, the substrate 100 is heated to
50.degree. C. to 200.degree. C. At the time of the film-forming
process, the film-forming container 11 is maintained in a vacuum
state. Further, the high-frequency power supply 16 supplies a
high-frequency current at a predetermined frequency to the plate
electrode 12.
[0032] The stage 14 comprises a vertically movable mechanism, and
at the time of the film-forming process, processing is performed
when the stage 14 is at the highest elevated position. Further, the
conductive susceptor 50 configured to hold the substrate 100 is
arranged on the stage 14. Thus, the substrate 100 is held on the
susceptor 50, and the high-frequency power supply 16 supplies a
high-frequency current at a predetermined frequency to the plate
electrode 12, whereby plasma is generated between the plate
electrode 12 and the susceptor 50.
[0033] Next, a gas inlet 20 to which the source gas, reaction gas
and purge gas are introduced will be described. The gas inlet 20
allows the source gas, reaction gas and purge gas to be supplied
into the film-forming container 11 in accordance with the process.
In addition, the injector 21 is attached to a gas inlet side
opening 25 of the film-forming container 11, and an injector
deposition prevention member 22 is inserted into the gas inlet side
opening 25 from inside the film-forming container 11 and is
attached so as to surround the gas inlet side opening 25.
[0034] Next, an outlet 30 will be described. The outlet 30 allows
the source gas, reaction gas and purge gas to be exhausted from the
film-forming container 11 in accordance with the process. The
outlet flange 31 is attached to a gas outlet side opening 33 of the
film-forming container 11, and an outlet deposition prevention
member 32 is inserted into the gas outlet side opening 33 from
inside the film-forming container 11 and is attached so as to
surround the gas outlet side opening 33. Further, the gas
introduced into the film-forming container 11 flows from the gas
inlet 20 toward the outlet 30 in accordance with the process.
Hereinafter, a direction along a direction of this gas flow will be
described as a side direction.
[0035] Next, detailed structures of the susceptor 50 and in the
vicinity of the susceptor 50 will be described with reference to
FIGS. 1 to 3.
[0036] FIG. 2 is an enlarged cross-sectional view showing an
example of a main part of the inert gas supply channel of the
atomic layer deposition apparatus shown in FIG. 1, and FIG. 3 is a
partially enlarged cross-sectional view and an enlarged plan view
showing an example of the structure of the inert gas supply channel
shown in FIG. 2. Note that FIG. 2 is also an enlarged
cross-sectional view of the vicinity of the susceptor 50 when
viewed from a holding surface of the injector 21 parallel to the
direction of the gas flowing from the gas inlet 20 toward the
outlet 30 shown in FIG. 1.
[0037] As shown in FIG. 2, in the atomic layer deposition apparatus
10 of the first embodiment, the susceptor 50 is arranged on the
stage 14, and the substrate 100 is held by the susceptor 50. The
susceptor 50 comprises an upper susceptor 52 configured to hold the
substrate 100 and a lower susceptor 51 configured to support the
upper susceptor 52. Further, the upper susceptor 52 comprises an
upper susceptor substrate holding portion (first susceptor) 52B
having a holding surface 52BA configured to hold the substrate 100,
and an upper susceptor peripheral portion (second susceptor) 52A
positioned in a periphery of the upper susceptor substrate holding
portion 52B and being arranged at a lower position than the holding
surface 52BA.
[0038] In addition, the lower susceptor 51 is supported by the
stage 14, and includes a lower susceptor peripheral portion 51A at
a lower position than the holding surface 52BA for the substrate
100 and a lower susceptor supporting portion 51B configured to hold
the upper susceptor 52. A stage stopper 17 is a member provided so
as to be in contact with an inner wall 11A of the four side walls
of the film-forming container 11, is configured to stop rising of
the stage 14 and, when in contact with the susceptor 50, is
configured to partition and form, in the film-forming container 11,
the film-forming space S in which the film-forming process is
performed and a transporting space T shown in FIG. 1 in which
transport of the substrate 100 is performed. Further, the
conductive upper susceptor 52 is arranged on the lower susceptor
supporting portion 51B and includes the upper susceptor substrate
holding portion 52B configured to hold the substrate 100, and the
upper susceptor peripheral portion 52A arranged in the periphery of
the upper susceptor substrate holding portion 52B and having a
surface at a lower position than the upper susceptor substrate
holding portion 52B. A susceptor deposition prevention member 15 is
provided on at least the upper susceptor peripheral portion 52A,
and the susceptor deposition prevention member 15 is provided on a
portion of the lower susceptor peripheral portion 51A and the upper
susceptor peripheral portion 52A in the atomic layer deposition
apparatus 10 of the first embodiment.
[0039] In addition, a side surface of the upper susceptor
peripheral portion 52A closer to the stage stopper 17 is positioned
more inward than a substrate-side side surface of the stage stopper
17, and the upper susceptor 52 and the lower susceptor 51 are fixed
to each other by a fixing screw 54 in the upper susceptor
peripheral portion 52A.
[0040] Here, an inert gas discharge portion 63 configured to supply
inert gas is attached to the upper susceptor peripheral portion
52A. As shown in FIG. 3, the inert gas discharge portion 63 is
formed in, for example, a frame-like manner so as to surround the
upper susceptor substrate holding portion 52B and is provided with
a plurality of inert gas supply ports 63A configured to supply the
inert gas upward. Further, the inert gas supply ports 63A
communicate with a lower inert gas supply channel 62A of the lower
susceptor supporting portion 51B.
[0041] That is, an inert gas supply channel G configured to supply
the inert gas from the outside is provided in the susceptor 50, the
inert gas discharge portion 63 is arranged at a position between
the upper susceptor substrate holding portion 52B and the upper
susceptor peripheral portion 52A, and the inert gas supply port 63A
communicating with the inert gas supply channel G is further formed
in the inert gas discharge portion 63.
[0042] In addition, as shown in FIG. 2, a gap between a side
surface of the upper susceptor substrate holding portion 52B and a
substrate-side side surface of the susceptor deposition prevention
member 15 configures an upper susceptor inert gas supply channel
64, and a gap between a lower surface of the substrate 100 and an
upper surface of the susceptor deposition prevention member 15
configures an inert gas discharge port 65. Namely, the inert gas
supply channel G configured to supply the inert gas to the
film-forming space S via the inert gas discharge port 65
constituted by a gap between the substrate 100 and the susceptor
deposition prevention member 15 and via the upper susceptor inert
gas supply channel 64 constituted by a gap between the upper
susceptor substrate holding portion 52B and the susceptor
deposition prevention member 15 is formed in the susceptor 50.
Further, an inert gas supply portion 61 configured to supply the
inert gas to the inert gas supply channel G of the susceptor 50 is
provided in the film-forming container 11.
[0043] The inert gas supply channel G formed in the susceptor 50 is
constituted by an upper inert gas supply channel 62B formed in the
upper susceptor 52 and the lower inert gas supply channel 62A
formed in the lower susceptor 51, and the upper inert gas supply
channel 62B and the lower inert gas supply channel 62A communicate
with each other.
[0044] As described above, in the atomic layer deposition apparatus
10 of the first embodiment, the inert gas supply channel G
configured to supply the inert gas from outside and being
constituted by the upper inert gas supply channel 62B and the lower
inert gas supply channel 62A is formed in the susceptor 50.
Further, an inert gas vent 66 connected to the film-forming
container 11 via the inert gas supply channel G and an inert gas
supply tube 53 is formed in the film-forming container 11.
[0045] A stage stopper deposition prevention member 24 is provided
on an upper surface of the stage stopper 17 provided on the inner
wall 11A of the film-forming container 11, and a side wall
deposition prevention member 26 is provided on the injector
deposition prevention member 22 on the same side as the inner wall
11A.
[0046] Here, details of problems of the first embodiment will be
described.
[0047] In each step of the film-forming process using the atomic
layer deposition method, gas of the next reactant is introduced
after waiting for the prior gas to be diffused. At this time, the
source gas (such as TMA) used is easily diffused, whereby the
source gas easily enters a small gap in the film-forming container
and forms a film. For example, the source gas or reaction gas
enters a small gap formed in the stage 14, the susceptor 50
provided in the film-forming container and members in the periphery
of the susceptor 50, whereby film deposition occurs in the small
gap. This film deposition causes generation of particles, resulting
in a problem in which properties of the thin film formed over the
substrate 100 are deteriorated. In order to suppress film
deposition, it is necessary to reduce a cross-sectional area of a
flow channel which becomes a gas entrance channel, increase a
distance of the flow channel, and also allow the inert gas to be
purged. However, there may be a case where the structure of the
apparatus does not allow reduction of the cross-sectional area of
the flow channel which becomes the gas entrance channel or does not
allow an increase in the distance of the flow channel. In such a
case, it is possible to reduce film deposition but would be
difficult to completely avoid film deposition.
[0048] In the film-forming apparatus such as a CVD apparatus,
excessive film in the chamber is removed by dry etching. Namely,
excessive film is removed without disassembling the chamber by
flowing a cooling gas (such as NF.sub.3) and forming plasma.
[0049] However, an alumina (Al.sub.2O.sub.3) film used in the
atomic layer deposition apparatus is subjected to a high
temperature process (for example, at 800.degree. C.) when dry
etching is performed, which is costly.
[0050] In addition, in the atomic layer deposition apparatus that
uses plasma to form an insulating film, the part to be partitioned
is insulated by deposition of the film, whereby the amount of the
high-frequency current flowed between the susceptor 50 and the
stage stopper 17 changes as the film-forming process is repeated,
resulting in a problem in which film-forming repeatability is
reduced. In addition, the high-frequency current flowed to the
susceptor 50 is concentrated in the vicinity of the stage stopper
17, whereby arcing is likely to occur in a portion where a gap or
unevennesses are present. Thus, it is necessary to minimize the
number of joints and screws for the deposition prevention plate
which become a source of arcing.
[0051] In addition, the number of deposition prevention plates
increases as the atomic layer deposition apparatus becomes larger,
resulting in a problem in which time required for maintenance
increases. Maintenance of the film-forming container 11 is
performed by releasing the top plate 42 of the film-forming
container 11 and reaching into the film-forming space S from above
the film-forming container 11; however, access to the deposition
prevention plates of the side surface of the stage stopper 17 and
in the vicinity of the susceptor at the time of maintenance is
difficult, whereby maintenance workability becomes very poor.
[0052] Thus, it is desired that the deposition prevention plate in
the vicinity of the susceptor 50 of the atomic layer deposition
apparatus has a structure in which film deposition to regions other
than the surface of the deposition prevention plate is suppressed
and in which the deposition prevention plate can be easily attached
and removed.
[0053] In the atomic layer deposition apparatus 10 of the first
embodiment, the susceptor deposition prevention member 15 is
provided on the lower susceptor peripheral portion 51A and the
upper susceptor peripheral portion 52A in a region inside the stage
stopper 17.
[0054] Next, a detailed structure of the periphery of the susceptor
50 will be further described.
[0055] In the atomic layer deposition apparatus 10, a distance
(distance a) between the side surface of the upper susceptor
substrate holding portion 52B and a side surface of the substrate
100 is preferably greater than or equal to 0.1 mm and less than or
equal to 10 mm. By making the distance a large, entry of the source
gas and reaction gas into the inert gas discharge port 65 is
suppressed, whereby film deposition on the upper susceptor
substrate holding portion 52B can be reduced. However, in a case
where the distance a is too large, a size of a region in which an
outer peripheral portion of the substrate 100 does not come in
contact with the upper susceptor substrate holding portion 52B
increases, whereby the temperature of the outer peripheral portion
of the substrate 100 is caused to decrease. Since edge exclusion of
the substrate 100 is typically set to 5 mm, a suitable value of the
distance a in the first embodiment is set to 5 mm.
[0056] In addition, the gap (distance b) between the side surface
of the upper susceptor substrate holding portion 52B and the
substrate-side side surface of the susceptor deposition prevention
member 15 is preferably greater than or equal to 0.1 mm and less
than or equal to 10 mm. By making the distance b small, entry of
the source gas and reaction gas into the upper susceptor inert gas
supply channel 64 is suppressed, whereby film deposition on the
upper susceptor substrate holding portion 52B and the upper
susceptor peripheral portion 52A is reduced. In a case where a
value of the distance b is too small, the side surface of the upper
susceptor substrate holding portion 52B and the susceptor
deposition prevention member 15 may interfere with each other
depending on assembly accuracy. Thus, a suitable value for the
distance b is necessary, and in the first embodiment, the distance
b is set to 0.5 mm.
[0057] In addition, an overlapping distance (distance c) of the
substrate 100 and the susceptor deposition prevention member 15 in
a horizontal direction is preferably greater than or equal to 0.1
mm and less than or equal to 10 mm. By making the distance c large,
entry of the source gas and reaction gas into the inert gas
discharge port 65 is suppressed. However, in a case where the value
of the distance b is small, the side surface of the upper susceptor
substrate holding portion 52B and the susceptor deposition
prevention member 15 may interfere with each other depending on
assembly accuracy. At this time, the distance c is determined by
the suitable values of the distances a and b, and thus, in the
first embodiment, the distance c is set to 4.5 mm.
[0058] In addition, the gap (distance d) between the lower surface
of the substrate 100 and the upper surface of the susceptor
deposition prevention member 15 is preferably greater than or equal
to 0.1 mm and less than or equal to 10 mm. By making the distance d
small, entry of the source gas and reaction gas into the inert gas
discharge port 65 is suppressed. In a case where a value of the
distance d is too small, the substrate 100 and the susceptor
deposition prevention member 15 may interfere with each other
depending on assembly accuracy. Thus, a suitable value for the
distance d is necessary, and in the first embodiment, the distance
d is set to 1 mm.
[0059] The upper susceptor peripheral portion 52A includes the
upper inert gas supply channel 62B communicating with the inert gas
supply port 63A, and a terminal end of the upper inert gas supply
channel 62B is connected to the lower inert gas supply channel 62A
provided in the lower susceptor 51. The lower inert gas supply
channel 62A and the upper inert gas supply channel 62B form a
through hole in the lower susceptor 51 and the upper susceptor 52,
and the inert gas can be supplied to the inert gas supply port 63A
by interposing, for example, an O-ring therebetween. The inert gas
supply tube 53 arranged on an outer peripheral side of the lower
susceptor 51 is connected to the lower inert gas supply channel
62A, and the other end of the inert gas supply tube 53 is connected
to the inert gas vent 66 provided in the film-forming container 11.
Further, the inert gas supply portion 61 provided outside the
film-forming container 11 is connected to the inert gas vent
66.
[0060] The inert gas supply tube 53 can be constituted by, for
example, a stainless steel tube, a bellows type flexible tube or
the like. When the substrate 100 is transported into or out from
the film-forming container 11, the stage 14 is vertically moved,
and it is necessary for the inert gas supply tube 53 to also follow
this vertical movement. The inert gas supply tube 53 also partially
configures the inert gas supply channel.
[0061] As shown in FIG. 3, the inert gas is preferably shower-fed
from an entire periphery of each of the upper susceptor inert gas
supply channel 64 and inert gas discharge port 65 by the inert gas
supply port 63A of the inert gas discharge portion 63. A single
inert gas supply portion 61 is provided in FIG. 3; however, it is
preferable to provide a plurality of inert gas supply portions 61.
A plurality of inert gas discharge ports 65 may be formed along an
entire periphery of the vicinity of the upper susceptor substrate
holding portion 52B, or the inert gas discharge port 65 may be
continuously formed along the entire periphery of the vicinity of
the upper susceptor substrate holding portion 52B.
[0062] In addition, a shower hole in each of the inert gas supply
ports 63A has a diameter that preferably falls within a range of 1
mm to 3 mm, where a diameter of approximately 1 mm is sufficient. A
pitch between the shower holes is preferably 10 mm to 200 mm. The
shower hole may be formed by providing a through hole in the upper
susceptor peripheral portion 52A, or a shower plate may be
individually formed and attached to the upper susceptor peripheral
portion 52A.
[0063] In addition, the lower susceptor 51 and the upper susceptor
52 may be fixed to each other by using, for example, a screw. Here,
a position of the fixing screw 54 is preferably in a portion of the
upper susceptor peripheral portion 52A. In a case where the fixing
screw 54 is present in the upper susceptor substrate holding
portion 52B, it is possible for its screw head to interfere with
the substrate 100. In addition, in a case where the screw head is
present at a lower position than an upper surface of the upper
susceptor substrate holding portion 52B, the portion of the upper
susceptor substrate holding portion 52B where the screw head is
present cannot come into contact with the substrate 100, whereby
the temperature is caused to decrease locally.
[0064] As shown in FIG. 2, in the inert gas discharge port 65 of
the first embodiment, the value of the distance (distance a)
between the side surface of the upper susceptor substrate holding
portion 52B and the side surface of the substrate 100 configuring
the inert gas discharge port 65 is set to 5 mm, considering
deterioration of temperature uniformity of the substrate 100.
Further, the value of the gap (distance d) between the lower
surface of the substrate 100 and the upper surface of the susceptor
deposition prevention member 15 is set to 1 mm, considering
interference of the substrate 100 and the susceptor deposition
prevention member 15. However, it is possible that a flow channel
width and a flow channel length are not sufficient for suppressing
entry of the source gas and reaction gas.
[0065] By increasing a supply amount of the inert gas, entry of the
source gas and reaction gas into the inert gas discharge port 65
can be reduced; however, increasing the flow rate affects gas
uniformity of the source gas and reaction gas and may deteriorate
uniformity of the film thickness and uniformity of the film
quality.
[0066] Since it is highly possible that completely suppressing
generation of powders in the gaps and completely suppressing film
deposition on the upper susceptor substrate holding portion 52B are
difficult, it is preferable that the upper susceptor 52 has a
structure that allows the upper susceptor 52 to be easily attached
and removed.
[0067] Thus, it is preferable that an end surface (side surface) of
an outer peripheral portion of the upper susceptor peripheral
portion 52A is in the film-forming space S at a position more
inward than a substrate-side end surface (side surface) of the
stage stopper 17. The stage stopper 17 is completely fixed to the
film-forming container 11 and may be difficult to attach or remove;
however, as long as the upper susceptor 52 has a smaller size than
the stage stopper 17, the upper susceptor 52 can be easily removed
upward without removing the stage stopper 17, whereby
maintainability of the film-forming container 11 can be
improved.
[0068] After the inert gas is heated to a temperature within
.+-.10% of a surface temperature of the stage 14, it is preferable
that the inert gas is discharged from the inert gas supply port 63A
and is further discharged via the inert gas discharge port 65. For
example, when the inert gas is supplied at room temperature in a
case where the stage is to be heated to 100.degree. C., an outer
periphery of each of the lower susceptor 51 and upper susceptor 52
is cooled, whereby temperature distribution of the substrate 100 is
reduced and uniformity of the film thickness and uniformity of the
film quality is deteriorated. In order to maintain the temperatures
of the lower susceptor 51 and upper susceptor 52 constant, it is
thus preferable to supply the inert gas at, for example, 90.degree.
C. to 110.degree. C.
[0069] According to the atomic layer deposition apparatus 10 of the
first embodiment, the susceptor deposition prevention member 15 is
provided on the susceptor 50 arranged on the stage 14, whereby film
deposition on the susceptor 50 can be suppressed.
[0070] Specifically, the susceptor deposition prevention member 15
is provided on an upper surface of the upper susceptor peripheral
portion 52A of the upper susceptor 52 configured to hold the
substrate 100 and on an upper surface of the lower susceptor
peripheral portion 51A of the lower susceptor 51, whereby film
deposition on the upper susceptor peripheral portion 52A and the
lower susceptor peripheral portion 51A and film deposition in a gap
between the upper susceptor peripheral portion 52A and the lower
susceptor peripheral portion 51A can be suppressed.
[0071] Particularly, the source gas such as TMA used in the atomic
layer deposition apparatus 10 has a strong diffusibility, whereby
the source gas can easily enter various gaps in the film-forming
container 11; however, since the susceptor 50 is covered by the
susceptor deposition prevention member 15, entry of the source gas
into the gaps of the susceptor 50 and in the vicinity of the
susceptor 50 can be prevented. As a result, generation of particles
formed by the thin film, powders and the like can be
suppressed.
[0072] In this manner, generation of particles in the film-forming
container 11 is suppressed, whereby film quality of the thin film
formed over the substrate 100 can be improved.
[0073] In addition, by arranging the side surface of the upper
susceptor peripheral portion 52A of the upper susceptor 52 at a
position more inward than a position of the substrate-side side
surface of the stage stopper 17, the upper susceptor 52 can be
easily attached and removed. As a result, maintenance workability
of the film-forming container 11 and the upper susceptor 52 can be
improved.
[0074] In addition, by forming the inert gas supply channel G
constituted by the lower inert gas supply channel 62A and the upper
inert gas supply channel 62B in the susceptor 50, the inert gas can
be flowed in the gap between the susceptor deposition prevention
member 15 and the upper susceptor substrate holding portion 52B and
the gap between the substrate 100 and the susceptor deposition
prevention member 15 at the time of the film-forming process.
[0075] In this manner, entry of the source gas into the vicinity of
the side surface of the susceptor deposition prevention member 15
can be prevented, whereby film deposition on the susceptor 50 can
be suppressed. As a result, frequency of maintenance of the
film-forming container 11 is reduced, whereby an operation rate of
the atomic layer deposition apparatus 10 can be improved.
[0076] In addition, by forming the inert gas supply channel G in
the susceptor 50, manufacturing cost can be reduced as compared to
a case where the inert gas supply channel is formed in the stage
14. Further, designing the stage 14 would be difficult in a case
where the inert gas supply channel is formed in the stage 14,
whereas designing the stage 14 is easier when the inert gas supply
channel is formed in the susceptor 50. In addition, a degree of
freedom can be increased when the inert gas supply channel is
formed in the susceptor 50 as compared to a case where the channel
is formed in the stage 14.
Atomic Layer Deposition Method
[0077] Next, a procedure (atomic layer deposition method) of the
thin film-forming process using the atomic layer deposition
apparatus 10 will be described.
[0078] FIG. 4 is a flowchart showing an example of the atomic layer
deposition method of the present embodiment, and FIGS. 5(a) to 5(d)
are cross-sectional views showing an example of the substrate in
the procedure of the thin film-forming process according to the
flowchart shown in FIG. 4.
[0079] First, the substrate 100 is mounted on the stage 14 provided
in the film-forming container 11 shown in FIG. 1.
[0080] Next, a source gas supply unit supplies the source gas into
the film-forming container 11 (step s1 shown in FIG. 4).
Specifically, the source gas is supplied to the gas inlet 20 of the
film-forming container 11 shown in FIG. 1 (step s1). The source gas
is, for example, TMA and is supplied into the film-forming
container 11. The source gas is supplied into the film-forming
container 11 for, for example, 0.1 seconds. As shown in FIG. 5(a),
in step s1, the source gas 110 is supplied into the film-forming
container 11 and is absorbed onto the substrate 100, whereby an
absorption layer 102 is formed.
[0081] In addition, in step s1, inert gas F such as nitrogen is
supplied from the inert gas supply portion 61 shown in FIG. 2 into
the film-forming container 11 shown in FIG. 1. Specifically, the
inert gas is supplied to the film-forming space S via the inert gas
supply channel G formed in the susceptor 50. In the first
embodiment, the inert gas F is constantly supplied into the
film-forming container 11 not only during step s1 but also during
steps s2 to s4 described below. In this manner, entry of the source
gas and reaction gas into the gap between the substrate 100 and the
susceptor deposition prevention member 15 and the gap between the
upper susceptor substrate holding portion 52B and the susceptor
deposition prevention member 15 can be reduced, whereby film
deposition in each of the gaps can be suppressed.
[0082] Next, supplying of the source gas 110 is stopped, and the
purge gas is supplied from the gas inlet 20 (step s2 shown in FIG.
4). The purge gas is supplied into the film-forming container 11.
The source gas 110 is discharged outside the film-forming container
11 from the outlet 30 of the film-forming container 11.
[0083] The purge gas is supplied into the film-forming container 11
for, for example, 0.1 seconds. Further, the outlet 30 allows the
source gas 110 and purge gas 112 in the film-forming container 11
to be exhausted. The outlet 30 allows the source gas 110 and purge
gas 112 in the film-forming container 11 to be exhausted for, for
example, 2 seconds. As shown in FIG. 5(b), in step s2, the purge
gas 112 is supplied into the film-forming container 11, whereby the
source gas 110 not absorbed onto the substrate 100 is purged from
the film-forming container 11. At this time, the inert gas F is
also supplied from the inert gas supply portion 61.
[0084] Next, the reaction gas is supplied into the film-forming
container 11 (step s3 shown in FIG. 4). Specifically, the reaction
gas is supplied through the gas inlet 20 (step s3). The reaction
gas passes through a channel of the gas inlet 20 and is supplied
into the film-forming container 11. The reaction gas is supplied
into the film-forming container 11 for, for example, 1 second. As
shown in FIG. 5(c), in step s3, reaction gas 114 is supplied into
the film-forming container 11, whereby a desired thin layer 104 is
formed over the surface of the substrate 100. The thin layer 104
is, for example, an organic EL protective film. In addition, the
inert gas F is supplied from the inert gas supply portion 61 also
during step s3.
[0085] Next, supplying of the reaction gas is stopped, and the
purge gas is supplied to the gas inlet 20 (step s4 shown in FIG.
4). The purge gas 112 is supplied into the film-forming container
11. The purge gas 112 is discharged outside the film-forming
container 11 from the outlet 30. The purge gas is supplied into the
film-forming container 11 for, for example, 0.1 seconds. The outlet
30 allows the reaction gas 114 and purge gas 112 in the
film-forming container 11 to be exhausted outside the film-forming
container 11. As shown in FIG. 5(d), in step s4, the purge gas 112
is supplied into the film-forming container 11, whereby the
reaction gas 114 is purged from the film-forming container 11. At
this time, the inert gas F is also supplied from the inert gas
supply portion 61.
[0086] By performing steps s1 to s4 described above, the thin layer
104 having a single atomic layer is formed over the substrate 100.
Thereafter, steps s1 to s4 are repeated a predetermined number of
times such that the thin layer 104 having a desired film thickness
can be formed.
[0087] As described above, in the atomic layer deposition apparatus
10 of the first embodiment, the inert gas F is supplied
(introduced) from the inert gas supply portion 61 into the
film-forming container 11 via the inert gas supply channel G formed
in the susceptor 50 during the film-forming process (during steps
s1 to s4). In this manner, the inert gas F is supplied to a side
portion of the susceptor 50 and the film-forming space S above the
stage 14.
[0088] More specifically, as shown in FIG. 2, the inert gas is
supplied from the inert gas supply portion 61 and the inert gas F
is flowed in the gap between the substrate 100 and the susceptor
deposition prevention member 15 and the gap between the upper
susceptor substrate holding portion 52B and the susceptor
deposition prevention member 15 during the film-forming process,
whereby the amount of film deposition on the upper susceptor
substrate holding portion 52B can be reduced. As a result,
frequency of cleaning the inside of the film-forming container 11
by wet etching can be reduced.
[0089] In addition, in the atomic layer deposition method of the
first embodiment, the inert gas F is continuously flowed in the gap
between the substrate 100 and the susceptor deposition prevention
member 15 and the gap between the upper susceptor substrate holding
portion 52B and the susceptor deposition prevention member 15
during the film-forming process.
[0090] In this manner, a constant pressure can be constantly
maintained in the film-forming container 11 during the film-forming
process. Particles are likely to generate when the pressure in the
film-forming container 11 fluctuates, whereby film quality of the
thin film formed over the substrate 100 deteriorates; however, in
the atomic layer deposition method of the first embodiment, the
inert gas F is continuously flowed during the film-forming process,
whereby the pressure in the film-forming container 11 can be
constantly maintained and generation of particles can be
reduced.
[0091] As a result, film quality of the thin film formed over the
substrate 100 can be improved.
[0092] In addition, by flowing the inert gas F in each of the gaps,
entry of the source gas 110 and reaction gas 114 into each of the
gaps can be prevented, whereby film deposition on the stage stopper
17 and each of the gaps can be suppressed.
[0093] Here, a result of an evaluation performed on formation of an
AlON thin film over a large area glass substrate having a size of
370 mm.times.470 mm by using the atomic layer deposition apparatus
10 according to the first embodiment will be described. Values for
the atomic layer deposition apparatus 10 were set to the
following.
[0094] Distance a: 5 mm, distance b: 0.5 mm, distance c: 4.5 mm,
distance d: 1 mm, diameter of shower hole: 1 mm, pitch between
shower holes: 100 mm, stage temperature: 100.degree. C., inert gas
temperature: 100.degree. C., and inert gas flow rate: 500 sccm.
[0095] In addition, TMA was used as a liquid source (source gas, Al
source), and oxygen plasma and nitrogen plasma were used as the
reaction gas. Film-forming was performed according to the sequence
shown in FIG. 4. The pressure in the film-forming container 11 was
set to 100 Pa, 1000 sccm of nitrogen was supplied from the upper
inert gas supply channel 62B and the lower inert gas supply channel
62A as the inert gas F, and the inert gas F was constantly supplied
during the film-forming sequence.
[0096] After the film-forming process was performed such that the
film thickness in the film-forming container 11 was 20 .mu.m, film
deposition of 200 nm on the upper susceptor substrate holding
portion 52B was observed; however, no generation of powders was
observed. In a case where a 2 .mu.m film is deposited on the
susceptor 50 of the first embodiment, it is known that particles
are generated by the susceptor 50 depending on the material used
and the film quality of the deposited film.
Rectified Under Rule 91, 26 Sep. 2017
[0097] In an atomic layer deposition apparatus in which the inert
gas is not supplied into the film-forming container during the
film-forming process, generation of powders was observed when the
film thickness in the film-forming container reached 20 .mu.m, and
it was necessary to perform maintenance after disassembling the
stage stopper every time this was observed. In contrast, the atomic
layer deposition apparatus 10 of the first embodiment can be free
of maintenance until the film thickness in the film-forming
container 11 reaches 200 .mu.m which is ten times the film
thickness of the atomic layer deposition apparatus in which the
inert gas is not supplied.
[0098] Further, it was confirmed that maintainability can be
significantly improved since the upper susceptor 52 can be easily
attached and removed at the time of maintenance.
Second Embodiment
Configuration of Atomic Layer Deposition Apparatus
[0099] FIG. 6 is an enlarged cross-sectional view showing an
example of a structure of a main part of the atomic layer
deposition apparatus of a second embodiment, and FIG. 7 is an
enlarged cross-sectional view showing an example of a main part of
the inert gas supply channel of the atomic layer deposition
apparatus shown in FIG. 6.
[0100] In the atomic layer deposition apparatus 10 of the second
embodiment, an inert gas supply channel connecting the inert gas
supply channel formed in the lower susceptor 51 (lower susceptor
supporting portion 51B) and the inert gas vent 66 formed in the
film-forming container 11 is formed in the stage stopper 17.
[0101] Here, features of the structure of the main part of the
atomic layer deposition apparatus 10 of the second embodiment will
be described with reference to FIGS. 6 and 7. As in the atomic
layer deposition apparatus 10 of the first embodiment, the
susceptor 50 comprises the upper susceptor substrate holding
portion (first susceptor) 52B configured to hold the substrate 100,
and the upper susceptor peripheral portion (second susceptor) 52A
arranged on the periphery of the upper susceptor substrate holding
portion 52B. Further, the susceptor deposition prevention member 15
is provided so as to extend over the upper susceptor peripheral
portion 52A and a portion of the lower susceptor peripheral portion
51A.
[0102] Further, a stage stopper gas supply channel 17A serving as
an inert gas supply channel communicating with the lower inert gas
supply channel 62A formed in the lower susceptor supporting portion
51B is formed in the stage stopper 17, and the inert gas is
supplied to the film-forming space S via the lower inert gas supply
channel 62A of the lower susceptor 51 and via the stage stopper gas
supply channel 17A serving as the inert gas supply channel of the
stage stopper 17 during the film-forming process.
[0103] Namely, as shown in FIG. 7, in the atomic layer deposition
apparatus 10 of the second embodiment, the lower inert gas supply
channel 62A formed in the lower susceptor 51 is connected to the
stage stopper gas supply channel 17A formed in the stage stopper
17, and the stage stopper gas supply channel 17A further
communicates with the inert gas vent 66 of the film-forming
container 11. Therefore, the inert gas supplied from the inert gas
supply portion 61 of the film-forming container 11 is supplied to
the film-forming space S via the stage stopper gas supply channel
17A of the stage stopper 17 and via the lower inert gas supply
channel 62A of the lower susceptor 51.
[0104] In addition, the upper susceptor peripheral portion 52A and
the lower susceptor supporting portion 51B are fixed to each other
by the fixing screw 54 at a position between the substrate-side
side surface of the stage stopper 17 and an end portion of the
substrate 100. More specifically, the upper susceptor peripheral
portion 52A is arranged at a position between the substrate-side
side surface of the stage stopper 17 and the side surface of the
upper susceptor substrate holding portion 52B just below the
substrate, and the upper susceptor peripheral portion 52A and the
lower susceptor supporting portion 51B are fixed to each other by
the fixing screw 54 at the position between the substrate-side side
surface of the stage stopper 17 and the side surface of the upper
susceptor substrate holding portion 52B just below the substrate
100.
[0105] In addition, in a case where the atomic layer deposition
apparatus 10 is configured to perform the film-forming process by
using plasma, the conductive susceptor 50 (lower susceptor
peripheral portion 51A) and the stage stopper 17 are electrically
connected to each other via a metal O-ring 55. That is, the plate
electrode 12 is arranged at a position facing the stage 14, the
stage 14 and the susceptor 50 are electrically connected to each
other, and the metal O-ring 55 is provided at a contact portion
between the lower susceptor peripheral portion 51A of the lower
susceptor 51 and the stage stopper 17. In this manner, the stage
stopper 17 and the lower susceptor peripheral portion 51A are
electrically connected to each other via the metal O-ring 55.
[0106] Other structures of the atomic layer deposition apparatus 10
of the second embodiment are the same as those of the atomic layer
deposition apparatus 10 of the first embodiment, and thus,
redundant descriptions thereof are omitted.
Atomic Layer Deposition Method
[0107] The film-forming process is performed by using the atomic
layer deposition apparatus 10 comprising the above-described main
structure.
[0108] Note that the procedure of the film-forming process is the
same as the procedure (atomic layer deposition method) of the first
embodiment described with reference to FIGS. 4 and 5.
[0109] First, the substrate 100 is mounted on the stage 14 provided
in the film-forming container 11 shown in FIG. 6.
[0110] Next, the source gas supply unit supplies the source gas
into the film-forming container 11 (step s1 shown in FIG. 4).
Specifically, the source gas is supplied to the gas inlet 20 of the
film-forming container 11 shown in FIG. 6 (step s1). The source gas
is, for example, TMA and is supplied into the film-forming
container 11. The source gas is supplied into the film-forming
container 11 for, for example, 0.1 seconds. As shown in FIG. 5(a),
in step s1, the source gas 110 is supplied into the film-forming
container 11 and is absorbed onto the substrate 100, whereby the
absorption layer 102 is formed.
[0111] In addition, in step s1, the inert gas F such as nitrogen is
supplied from the inert gas supply portion 61 shown in FIG. 7 into
the film-forming container 11 via the stage stopper gas supply
channel 17A of the stage stopper 17. In the second embodiment, the
inert gas F is constantly supplied into the film-forming container
11 not only during step s1 but also during steps s2 to s4 described
below. In this manner, entry of the source gas into the gap between
the substrate 100 and the susceptor deposition prevention member 15
and the gap between the upper susceptor substrate holding portion
52B and the susceptor deposition prevention member 15 can be
reduced, whereby film deposition in each of the gaps can be
suppressed.
[0112] Next, supplying of the source gas 110 is stopped, and the
purge gas is supplied from the gas inlet 20 (step s2 shown in FIG.
4). The purge gas is supplied into the film-forming container 11.
The source gas 110 is discharged outside the film-forming container
11 from the outlet 30 (see FIG. 1) of the film-forming container
11.
[0113] The purge gas is supplied into the film-forming container 11
for, for example, 0.1 seconds. Further, the outlet 30 allows the
source gas 110 and purge gas 112 in the film-forming container 11
to be exhausted. The outlet 30 allows the source gas 110 and purge
gas 112 in the film-forming container 11 to be exhausted for, for
example, 2 seconds. As shown in FIG. 5(b), in step s2, the purge
gas 112 is supplied into the film-forming container 11, whereby the
source gas 110 not absorbed onto the substrate 100 is purged from
the film-forming container 11. At this time, the inert gas F is
also supplied from the inert gas supply portion 61.
[0114] Next, the reaction gas is supplied into the film-forming
container 11 (step s3 shown in FIG. 4). Specifically, the reaction
gas is supplied through the gas inlet 20 (step s3). The reaction
gas passes through the channel of the gas inlet 20 and is supplied
into the film-forming container 11. The reaction gas is supplied
into the film-forming container 11 for, for example, 1 second. As
shown in FIG. 5(c), in step s3, the reaction gas 114 is supplied
into the film-forming container 11, whereby a desired thin layer
104 is formed over the surface of the substrate 100. The thin layer
104 is, for example, an organic EL protective film. In addition,
the inert gas F is supplied from the inert gas supply portion 61
also during step s3.
[0115] Next, supplying of the reaction gas is stopped, and the
purge gas is supplied to the gas inlet 20 (step s4 shown in FIG.
4). The purge gas 112 is supplied into the film-forming container
11. The purge gas 112 is discharged outside the film-forming
container 11 from the outlet 30. The purge gas is supplied into the
film-forming container 11 for, for example, 0.1 seconds. The outlet
30 allows the reaction gas 114 and purge gas 112 in the
film-forming container 11 to be exhausted outside the film-forming
container 11. As shown in FIG. 5(d), in step s4, the purge gas 112
is supplied into the film-forming container 11, whereby the
reaction gas 114 is purged from the film-forming container 11. At
this time, the inert gas F is also supplied from the inert gas
supply portion 61.
[0116] By performing steps s1 to s4 described above, the thin layer
104 having a single atomic layer is formed over the substrate 100.
Thereafter, steps s1 to s4 are repeated a predetermined number of
times such that the thin layer 104 having a desired film thickness
can be formed.
[0117] As described above, in the atomic layer deposition apparatus
10 of the second embodiment, the inert gas F is supplied
(introduced) from the inert gas supply portion 61 into the
film-forming container 11 via the stage stopper gas supply channel
17A formed in the stage stopper 17 during the film-forming process
(during steps s1 to s4). In this manner, the inert gas F is
supplied to the side portion of the susceptor 50 and the
film-forming space S. Therefore, the amount of film deposition on
the upper susceptor substrate holding portion 52B can be reduced.
As a result, frequency of cleaning the inside of the film-forming
container 11 by wet etching can be reduced.
[0118] In addition, in the atomic layer deposition method of the
second embodiment, the inert gas F is continuously flowed in the
gap between the substrate 100 and the susceptor deposition
prevention member 15 and the gap between the upper susceptor
substrate holding portion 52B and the susceptor deposition
prevention member 15 during the film-forming process.
[0119] In this manner, a constant pressure can be constantly
maintained in the film-forming container 11 during the film-forming
process, as in the first embodiment. Particles are likely to
generate when the pressure in the film-forming container 11
fluctuates, whereby film quality of the thin film formed over the
substrate 100 deteriorates; however, in the atomic layer deposition
method of the second embodiment, the inert gas F is continuously
flowed during the film-forming process, whereby the pressure in the
film-forming container 11 can be constantly maintained and
generation of particles can be reduced.
[0120] As a result, film quality of the thin film formed over the
substrate 100 can be improved.
[0121] In addition, by flowing the inert gas F in each of the gaps,
entry of the source gas 110 and reaction gas 114 into each of the
gaps can be prevented, whereby film deposition in each of the gaps
can be suppressed.
[0122] In addition, in the atomic layer deposition apparatus 10 of
the second embodiment, the stage stopper gas supply channel 17A
serving as the inert gas supply channel is formed in the stage
stopper 17 fixed to the film-forming container 11. In this manner,
it is possible to avoid a gas piping tube to be directly connected
to the lower inert gas supply channel 62A of the lower susceptor
51, and there would be no need to consider abrasion caused by
expansion and contraction of the gas piping tube that occurs when
the stage 14 is vertically moved. Further, the metal O-ring 55 can
provide conduction between the stage stopper 17 and the lower
susceptor peripheral portion 51A as well as sealing the contact
portion between the stage stopper 17 and the lower susceptor
peripheral portion 51A.
[0123] In addition, in the atomic layer deposition apparatus 10 of
the second embodiment, by arranging the upper susceptor peripheral
portion 52A at a position between the substrate-side side surface
of the stage stopper 17 and the side surface of the upper susceptor
substrate holding portion 52B just below the substrate, that is, at
a position more inward than the position of the substrate-side side
surface of the stage stopper 17, the upper susceptor 52 can be
easily attached and removed. As a result, maintenance workability
of the film-forming container 11 and the upper susceptor 52 can be
improved.
[0124] In the foregoing, the invention made by the present
inventors has been concretely described based on the embodiments.
However, it is needless to say that the present invention is not to
be limited to the foregoing embodiments, and various modifications
and alterations can be made within the scope of the present
invention.
[0125] For example, the atomic layer deposition apparatus 10
described in the first and second embodiments may be configured to
perform the film-forming process by using plasma, or may be
configured to perform the film-forming process without using
plasma.
[0126] In addition, in the first and second embodiments, a case
where the thin film formed over the substrate 100 is an organic EL
protective film has been described by way of example; however, the
thin film may be, for example, a gate insulating film or the like
of a MOSFET (Metal Oxide Semiconductor Field Effect
Transistor).
[0127] Further, in the description of the foregoing embodiments,
the first and second embodiments were described separately;
however, the embodiments are not irrelevant to each other. For
example, the first and second embodiments may be combined and
applied to the present invention.
LIST OF REFERENCE SIGNS
[0128] 10: atomic layer deposition apparatus
[0129] 11: film-forming container
[0130] 14: stage
[0131] 15: susceptor deposition prevention member
[0132] 17: stage stopper
[0133] 17A: stage stopper gas supply channel
[0134] 24: stage stopper deposition prevention member
[0135] 50: susceptor
[0136] 51: lower susceptor
[0137] 52: upper susceptor
[0138] 52A: upper susceptor peripheral portion (second
susceptor)
[0139] 52B: upper susceptor substrate holding portion (first
susceptor)
[0140] 62A: lower inert gas supply channel
[0141] 62B: upper inert gas supply channel
[0142] 100: substrate
* * * * *